drivers/gpu/drm/i915/gvt/page_track.c

   1 /*
   2  * Copyright(c) 2011-2017 Intel Corporation. All rights reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23 #include "i915_drv.h"
  24 #include "gvt.h"
  25
  26 /**
  27  * intel_vgpu_find_page_track - find page track rcord of guest page
  28  * @vgpu: a vGPU
  29  * @gfn: the gfn of guest page
  30  *
  31  * Returns:
  32  * A pointer to struct intel_vgpu_page_track if found, else NULL returned.
  33  */
  34 struct intel_vgpu_page_track *intel_vgpu_find_page_track(
  35                 struct intel_vgpu *vgpu, unsigned long gfn)
  36 {
  37         return radix_tree_lookup(&vgpu->page_track_tree, gfn);
  38 }
  39
  40 /**
  41  * intel_vgpu_register_page_track - register a guest page to be tacked
  42  * @vgpu: a vGPU
  43  * @gfn: the gfn of guest page
  44  * @handler: page track handler
  45  * @priv: tracker private
  46  *
  47  * Returns:
  48  * zero on success, negative error code if failed.
  49  */
  50 int intel_vgpu_register_page_track(struct intel_vgpu *vgpu, unsigned long gfn,
  51                 gvt_page_track_handler_t handler, void *priv)
  52 {
  53         struct intel_vgpu_page_track *track;
  54         int ret;
  55
  56         track = intel_vgpu_find_page_track(vgpu, gfn);
  57         if (track)
  58                 return -EEXIST;
  59
  60         track = kzalloc(sizeof(*track), GFP_KERNEL);
  61         if (!track)
  62                 return -ENOMEM;
  63
  64         track->handler = handler;
  65         track->priv_data = priv;
  66
  67         ret = radix_tree_insert(&vgpu->page_track_tree, gfn, track);
  68         if (ret) {
  69                 kfree(track);
  70                 return ret;
  71         }
  72
  73         return 0;
  74 }
  75
  76 /**
  77  * intel_vgpu_unregister_page_track - unregister the tracked guest page
  78  * @vgpu: a vGPU
  79  * @gfn: the gfn of guest page
  80  *
  81  */
  82 void intel_vgpu_unregister_page_track(struct intel_vgpu *vgpu,
  83                 unsigned long gfn)
  84 {
  85         struct intel_vgpu_page_track *track;
  86
  87         track = radix_tree_delete(&vgpu->page_track_tree, gfn);
  88         if (track) {
  89                 if (track->tracked)
  90                         intel_gvt_hypervisor_disable_page_track(vgpu, gfn);
  91                 kfree(track);
  92         }
  93 }
  94
  95 /**
  96  * intel_vgpu_enable_page_track - set write-protection on guest page
  97  * @vgpu: a vGPU
  98  * @gfn: the gfn of guest page
  99  *
 100  * Returns:
 101  * zero on success, negative error code if failed.
 102  */
 103 int intel_vgpu_enable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
 104 {
 105         struct intel_vgpu_page_track *track;
 106         int ret;
 107
 108         track = intel_vgpu_find_page_track(vgpu, gfn);
 109         if (!track)
 110                 return -ENXIO;
 111
 112         if (track->tracked)
 113                 return 0;
 114
 115         ret = intel_gvt_hypervisor_enable_page_track(vgpu, gfn);
 116         if (ret)
 117                 return ret;
 118         track->tracked = true;
 119         return 0;
 120 }
 121
 122 /**
 123  * intel_vgpu_enable_page_track - cancel write-protection on guest page
 124  * @vgpu: a vGPU
 125  * @gfn: the gfn of guest page
 126  *
 127  * Returns:
 128  * zero on success, negative error code if failed.
 129  */
 130 int intel_vgpu_disable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
 131 {
 132         struct intel_vgpu_page_track *track;
 133         int ret;
 134
 135         track = intel_vgpu_find_page_track(vgpu, gfn);
 136         if (!track)
 137                 return -ENXIO;
 138
 139         if (!track->tracked)
 140                 return 0;
 141
 142         ret = intel_gvt_hypervisor_disable_page_track(vgpu, gfn);
 143         if (ret)
 144                 return ret;
 145         track->tracked = false;
 146         return 0;
 147 }
 148
 149 /**
 150  * intel_vgpu_page_track_handler - called when write to write-protected page
 151  * @vgpu: a vGPU
 152  * @gpa: the gpa of this write
 153  * @data: the writed data
 154  * @bytes: the length of this write
 155  *
 156  * Returns:
 157  * zero on success, negative error code if failed.
 158  */
 159 int intel_vgpu_page_track_handler(struct intel_vgpu *vgpu, u64 gpa,
 160                 void *data, unsigned int bytes)
 161 {
 162         struct intel_vgpu_page_track *page_track;
 163         int ret = 0;
 164
 165         mutex_lock(&vgpu->vgpu_lock);
 166
 167         page_track = intel_vgpu_find_page_track(vgpu, gpa >> PAGE_SHIFT);
 168         if (!page_track) {
 169                 ret = -ENXIO;
 170                 goto out;
 171         }
 172
 173         if (unlikely(vgpu->failsafe)) {
 174                 /* Remove write protection to prevent furture traps. */
 175                 intel_vgpu_disable_page_track(vgpu, gpa >> PAGE_SHIFT);
 176         } else {
 177                 ret = page_track->handler(page_track, gpa, data, bytes);
 178                 if (ret)
 179                         gvt_err("guest page write error, gpa %llx\n", gpa);
 180         }
 181
 182 out:
 183         mutex_unlock(&vgpu->vgpu_lock);
 184         return ret;
 185 }